Potential Toxic Effects of  Vitamins When Given to Birds in Excess

Potential Toxic Effects of  Vitamins When Given to Birds in Excess

Last Updated on by Catherine Tobsing

 Below is a listing of Potential Toxic Effects of Vitamins when given in Excess
The following information is compiled from AVIAN MEDICINE: Principles and Applications by Ritchie, Harrison and Harrison

Vitamin A: Recommended daily allowances 
Min: 2500.00 IU/kg     Recommended: 5000.00 IU/KG*
Vitamin A: 20-100 times required amount
Weight loss
Decreased food intake
Swelling and/or crusting eyelids
Inflammation of the mouth
Inflammation of the nares
Decreased bone strength
Hepatopathy (excess storage in the liver)

Vitamin D3: Recommended daily allowances
Min: 500.00 IU/kg      Recommended: 1000.00 IU/kg*
Vitamin D3: 4-10 times the required amount
Increased calcium absorption
Increased bone resorption
Decreased PTH
Mineralization of soft tissue
Nephrocalcemia (excess calcium to the kidneys)

Vitamin E: Recommended daily allowances
Min: 15.00 IU/kg       Recommended: 20.00*
Vitamin E:  100 times required
Decreased growth
Increased prothrombin time (increased time for blood to coagulate)
Decreased bone mineralization
Decreased liver storage of vitamin A

Vitamin K: Recommended daily allowances
Min: 0.80 ppm     Recommended: 1.00 ppm
Vitamin K: 1000 times required amount
High mortality

Niacin: Recommended daily allowances
Min: 40.00 ppm     Recommended: 75.00 ppm
Niacin: 10 times required amount
Flushing – vasodilation

Pyridoxine: Recommended daily allowances
Min: 4.00 ppm       Recommended: 10.00 ppm
Pyridoxine: 50 times the required amount
Decreased egg production

Choline Chloride: Recommended daily allowances
Min: 750.00 ppm     Recommended: 1000.00 ppm
Choline Chloride: 2 times required amount
Increased mortality
Decreased use of Vitamin B6

Calcium: Recommended daily allowances
Min: 0.30 %     Recommended: 0.50%*
Calcium: 2.5% in excess of diet
Visceral gout
Renal gout
Decreased food intake

Magnesium: Recommended daily allowances
Min: 5000.00 ppm      Recommended: 600.00 ppm
Magnesium: 20 times the required amount
Decreased growth
Decreased egg production
Decreased egg quality

Manganese: Recommended daily allowances
Min: 60.00 ppm     Recommended: 75.00 ppm
Manganese: 20-50 times required amount
Iron deficiency

Selenium: Recommended daily allowances
Min: 0.10 ppm    Recommended: 0.10 ppm
Selenium: 50 times the required amount
Decreased weight gain
Weight loss
100 times required amount
Decreased egg weight
Decreased hatchability
Severe Excess
Blind staggers
Pulmonary congestion/edema
Liver cirrhosis

Copper: Recommended daily allowances
Min: 6.00 ppm    Recommended: 8.00 ppm
Copper: 50 times required
Decreased growth
Accumulates in liver

Zinc: Recommended daily allowances
Min: 40ppm       Recommended: 50 ppm
Zinc: 10-20 times the required amount
Decreased food intake
Decreased bone mineralization

NOTE: Increased levels are suggested for growth/breeding diets due primarily to the high requirements for adequate chick growth as opposed to increased demands for low-level breeding.*

NOTE: Not included in this list are phosphorus, potassium, sodium, chloride, iron and iodine.  
NOTE: Toxicity unlikely because the following are water soluble nutrients and not stored in the body.

Thiamine (rapidly excreted by kidneys)
Riboflavin (rapidly excreted by kidneys0
Pantothenic acid
Folic Acid
Vitamin C

Vitamin C:  A healthy bird is able to synthesize (manufacture) its own vitamin C.  When there is hepatic (liver) damage there is a need for increased Vit. C to compensate for the lowered synthesizing of this nutrient in the body.

Vitamin D: Disease that affects the liver and kidneys, the enzymes required to produce the metabolically active form of vitamin D3 are impaired, thus the bird would benefit from FSL (Full Spectrum) therapy.

Vitamin K:  Vitamin K is synthesized from the intestinal flora in the intestinal tract. Antibiotic treatments can interfere with this so it may be necessary to provide vitamin K.

Vitamin B Complex: In the case of a bird that is anorectic may be beneficial to provide additional B vitamins, especially thiamine.  Other water soluble vitamins such as riboflavin, pyndoxine and folic acid are important for protein and energy metabolism, therefore these vitamins have increased importance in a disease state.

Zinc: If the bird is nutrient deficient zinc will improve healing and is an important component in protein synthesis.  

Therefore zinc is necessary for the maintenance of the immune system and phagocytic activity. Some interesting facts on Zinc from Dr. Harrisons site: Zinc is a cofactor for the antioxidant enzyme superoxide dismutase.
Zinc plays a role in cell division, cell stability, protein metabolism, and carbohydrate digestion. It aids in wound healing and lymphocyte productions. Deficiency can reduce the number or T cells and decrease natural killer cell activity. 

Copper enhances the development of red and white blood cells. Deficiency reduces the maturation of lymphocytes. Magnesium is crucial for lymphocyte growth. Deficiency reduces the levels of immunoglobulin and antibody forming cells and promotes production of free radicals and lipid peroxidation.

Some Common Terms:
Hypovitaminosis means deficiency of one or more essential vitamins.

Hypervitaminosis means a condition produced by ingestion of excessive amounts of vitamins. There are 2 categories of vitamins: 
Fat-soluble vitamins, which are: A, D, E, and K. Fat-soluble vitamins are stored in the body, and build up in the liver and fatty tissues.
Feeding excessive amounts of vitamins (such as a pellets diet or fortified diet with supplemental vitamins) can cause the fat soluble vitamins to build up an allergic reaction or toxicity.

In either case this can cause an intense itch under the skin which results in plucking to relieve the itch. Also some foods that have corn can cause allergic reactions that contribute to plucking.  If plucking is around the flank of the bird this could indicate an irritation to the kidneys. 

Water-soluble vitamin/nutrients are: The B family (B1, B2, B3, B5, B6, B12) Biotin, Choline, Folic acid, Insotol, PABA, C, P (bioflavonoids). Water-soluble nutrients are NOT stored in the body. They are excreted daily, thus they need to be constantly replenished during times of stress, molting, etc, and the best way to supplement is with Brewers Yeast.

The labeling can give a clue to distinguish between natural and synthetic forms. If the ingredient is prefixed with a d-, this would be natural. If it is prefixed with either a dl- OR an l- this is a synthetic (chemical) component.EX: d-alpha-tocopherol = natural E dl-alfa-tocopherol = synthetic E

The natural form is identical to what the body makes and what is found in food, thus the body absorbs it better, and it stays in the system longer. 


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